Though Deschanel's sister, Zooey, was invited to reprise her role as Brennan's cousin Margaret Whitesell, her New Girl shooting schedule prevented an appearance. But the pews will still be overflowing with family and friends. "We have Ralph Waite [Booth's grandfather, Hank], Joanna Cassidy [Booth's mom, Marianne] and Ryan O'Neal [Brennan's dad, Max]," says Nathan, who also confirms the return of Booth's long-absent son, Parker (Ty Panitz). Booth's brother, Jared, we will learn, is unable to attend due to his military obligations.

Though new cast member Mather Zickel will be present at the ceremony as Booth's old priest friend, Aldo, Nathan says a mystery priest will also be on hand, perhaps to perform the service. And look forward to a return appearance from Cyndi Lauper as medium Avalon Harmonia, who will likely sing for the newlyweds.

The fun won't stop with the wedding, as the couple jets below the border for a honeymoon-themed episode with a twist. "It will be quite a unique situation," hints Nathan. "How could they have a wedding escape without a murder? The only way it could be better would be if there was an actual bow around the body."